When you’ve finished your trim, step back and inspect the hooves. They should be balanced, with even growth on both sides. The hinds should be growing at a slightly steeper angle than the fores.
Very important: your horse should never be less comfortable than before the trim. If he’s suddenly sore from trimming, you went too far. Find out where you went wrong and correct it next time.
It’s a good idea to use a note pad during inspection. Write down any concerns you have, and track the hooves’ progress. You’ll read the hooves better, and stay on top of any problems you need to address and rehabilitate.